Journal of Bionic Engineering

ISSN 1672-6529

CN 22-1355/TB

Editor-in-Chief : Luquan Ren Published by Science Press and Springer

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30 March 2005, Volume 2 Issue 1

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A Biomimetic Approach to Robot Locomotion in Unstructured and Slippery Environments

Giovanni La Spina¹, Thomas Hesselberg², John Williams², Julian F V Vincent²

J4. 2005, 2 (1): 1-14. DOI:

Abstract ( 1293 )

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While much attention has been given to biorobotics in recent years, not much of this has been given to the challenging subject of locomotion in slippery conditions. This study begins to rectify this by proposing a biomimetic approach to generating the friction required to give sufficient propulsive force on a slippery substrate. We took inspiration from a successful biological solution-that of applying hairlike structures to the propulsive appendages, similar to the setae found in nereid polychaetes living in muddy habitats. We began by examining the morphology and the mean locomotion parameters of one of the most common nereids: Nereis diversicolor. Following this study, we designed and fabricated a robotic system with appendages imitating the biological shape found in the worm. A flexible control system was developed to allow most of the locomotion parameters observed in the real worm to be applied to the robot. Experiments on three different natural substrates ranging from fine sand to gravel showed that, whereas a plate attached to the appendage generated most thrust on a small particle substrate, a bundle of artificial setae attached to the appendage generated most thrust on a large particle substrate. On all types of substrate tested, an appendage without any attachment did significantly worse than one with. This suggests that hairlike structures can be advantageous.

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Experiment about Drag Reduction of Bionic Non-smooth Surface in Low Speed Wind Tunnel

Tian Li-mei¹;Ren Lu-quan¹;Han Zhi-wu¹;Zhang Shi-cun²

J4. 2005, 2 (1): 15-24. DOI:

Abstract ( 1627 )

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The body surface of some organisms has nonsmooth structure, which is related to drag reduction in moving fluid. To imitate these structures, models with a nonsmooth surface were made. In order to find a relationship between drag reduction and the nonsmooth surface, an orthogonal design test was employed in a low speed wind tunnel. Six factors likely to influence drag reduction were considered, and each factor tested at three levels. The six factors were the configuration, diameter/bottom width, height/depth, distribution, the arrangement of the rough structures on the experimental model and the wind speed. It was shown that the nonsmooth surface causes drag reduction and the distribution of nonsmooth structures on the model, and wind speed, are the predominant factors affecting drag reduction. Using analysis of variance, the optimal combination and levels were obtained, which were a wind speed of 44 m/s, distribution of the nonsmooth structure on the tail of the experimental model, the configuration of riblets, diameter/bottom width of 1 mm, height/depth of 0.5 mm, arranged in a rhombic formation. At the optimal combination mentioned above, the 99% confidence interval for drag reduction was 11.13 % to 22.30%.

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Morphological Measurement and Analysis of Gymnarchus Niloticus

Hu Tian-jiang; Li Fei; Wang Guang-ming; Shen Lin-cheng

J4. 2005, 2 (1): 25-31. DOI:

Abstract ( 1608 )

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Gymnarchus niloticus swims by undulations of a longbased dorsal fin, while its body axis is in many cases held straight during swimming. This paper provides a brief relevant introduction to Gymnarchus niloticus, which belongs to the African freshwater electric eels but can inspire our bionic interests in propulsion besides its abilities in electric sensing. A special larva of Gymnarchus niloticus was morphologically measured by photographing it with a piece of scalecalibrated paper as the background. Then we analyzed the data by a CFDaided approach. Detailed flow patterns around the larva and a NACA0012 hydrofoil were respectively calculated and visualized at the Reynolds number of 7350 or so. The results show that the profile of Gymnarchus niloticus is well streamlined.

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Tangent Resistance of Soil on Moldboard and the Mechanism of Resistance Reduction of Bionic Moldboard

Deng Shi-qiao; Ren Lu-quan; Liu Yan; Han Zhi-wu

J4. 2005, 2 (1): 33-46. DOI:

Abstract ( 1504 )

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The tangent resistance on the interface of the soilmoldboard is an important component of the resistance to moving soil . We developed simplified mechanical models to analyze this resistance. We found that it is composed of two components, the frictional and adhesive resistances. These two components originate from the soil pore, which induced a capillary suction effect, and the soilmoldboard contact area produced tangent adhesive resistance. These two components varied differently with soil moisture. Thus we predicted that resistance reduction against soil exerted on the nonsmooth bionic moldboard is mainly due to the elimination of capillary suction and the reduction of physicalchemical adsorption of soil.

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Experiment Research on Binocular Perceptual Characteristics around Peripheral Vision for Development of Head Mounted Display with Wide View

Li Xiao-guang¹; Wu Jing-long²; Kawamura Sadao³

J4. 2005, 2 (1): 47-56. DOI:

Abstract ( 1353 )

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The head mounted display (HMD) is widely used in virtual reality technology. In common HMD, however, the binocular disparity is set to an equal fixed value in the entire range of view. Such HMD systems have several shortcomings when used for wide views. In this study, in order to realize a natural stereo sensation of HMD with wide view, we measure the characteristics of binocular stereo perception and binocular light perception. Results show that both the stereoacuity and light sensitivity decrease as the retina’s eccentricity increases from fovea to periphery. However, the decrease of the stereoacuity is more rapid than that of the light sensitivity. These results suggest that the binocular disparity at the peripheral field should be small, otherwise double images would be observed instead of a stereo view. Based on the results we develop a relative binocular stereoacuity model which can be applied for the design of HMD systems with wide view.

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